This invention relates to zig zag sewing machines, and in particular, to devices for controlling the lateral jogging of the sewing needle.
In designing a presser foot for a sewing machine, it is desirable to make the needle aperture therethrough as small as practicable such that the amount of unsupported material being sewn is kept to a minimum. However, while making zig zag stitches, the needle must move laterally forcing the operator to use a presser foot with a laterally elongated needle aperture. If the sewing machine is operated in the zig zag mode while a straight stitch presser foot is installed, the needle will be impeded by the presser foot causing the needle to break.
The U.S. Pat. Nos. 3,926,133 of Herron, et al and 3,985,087 of Herr, et al disclose systems for detecting the presence of a throat plate with a straight stitch aperture. Upon detecting this plate, the lateral jogging of the needle is inhibited. This invention thus seeks to apply these principles to the presser foot of a zig zag sewing machine.